• Journal of the Korean Society for Precision Engineering
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• v.18 no.12
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• pp.116-123
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• 2001

An automated injection molding design methodology has been developed to optimize multiple quality attributes, which are usually in conflict with each other, in injection molded parts. For the optimization, commercial CAE simulation tools and optimization techniques are integrated into the methodology. To decal with the multiple objective problem the relative closeness computed in TOPSIS(Technique for Order Preference by Similarity to Ideal Solution) is used as a performance measurement index for optimization multiple part defects. To attain robustness against process variation, Taguchi's quadratic loss function is introduced in the TOPSIS. Also, the modified complex method is used as an optimization tool to optimize objective function. The verification of the developed design methodology was carried out on simulation software with an actual model. Applied to production this methodology will be useful to companies in reducing their product development time and enhancing their product quality.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.5
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• pp.131-141
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• 2004

In this study a 3-D automatic die design supporting system for a bonnet panel has been developed using Pro/ROGRAM of the widespread CAD software Pro/ENGINEER A standard drawing die was defined in terms of the punch profile, the die face geometry, and the blank sheet size. The strip layout of a trimming die was defined, in addition, in terms of the trimming line and the locations of scrap cutters. Necessary relations for each design step are formulated and rules for bottom-up type 3-D die design were set up for the automatic design of drawing and trimming dies of a bonnet. With the input geometric data of punch profile, die face, and blank sheet, this 3-D design supporting system could complete the basic design process, in case of the bonnet drawing die, in a time 78% shorter than that required by a typical 2-D CAD system. The new design system showed remarkable design efficiency also when it was applied to the case of redesign and modification of the previous standard output for a different car type.

• The Mathematical Education
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• v.54 no.1
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• pp.65-81
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• 2015

The purpose of this study is to investigate the international trends of how the core competencies are reflected in mathematics curriculum, and to find the implications for the revision of Korean mathematics curriculum. For this purpose, the curriculum of the 9 countries including the U.S., Canada(Ontario), England, Australia, Poland, Singapore, China, Taiwan, and Hong Kong were thoroughly reviewed. It was found that a variety of core competencies were reflected in mathematics curricula in the 9 countries such as problem solving, reasoning, communication, mathematical knowledge and skills, selection and use of tools, critical thinking, connection, modelling, application of strategies, mathematical thinking, representation, creativity, utilization of information, and reflection etc. Especially the four most common core competencies (problem solving, reasoning, communication, and creativity) were further analyzed to identify their sub components. Consequently, it was recommended that new mathematics curriculum should consider reflecting various core competencies beyond problem solving, reasoning, and communication, and these core competencies are supposed to combine with mathematics contents to increase their feasibility. Finally considering the fact that software education is getting greater attention in the new curriculum, it is necessary to incorporate computational thinking into mathematics curriculum.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.10
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• pp.4933-4956
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• 2016

Use-After-Free (UAF) is a common lethal form of software vulnerability. By using tools such as Web Browser Fuzzing, a large amount of samples containing UAF vulnerabilities can be generated. To evaluate the threat level of vulnerability or to patch the vulnerabilities, automatic deduplication and exploitability determination should be carried out for these samples. There are some problems existing in current methods, including inadequate pertinence, lack of depth and precision of analysis, high time cost, and low accuracy. In this paper, in terms of key dangling pointer and crash context, we analyze four properties of similar samples of UAF vulnerability, explore the method of extracting and calculate clustering eigenvalues from these samples, perform clustering by fast search and find of density peaks on a large number of vulnerability samples. Samples were divided into different UAF vulnerability categories according to the clustering results, and the exploitability of these UAF vulnerabilities was determined by observing the shape of class cluster. Experimental results showed that the approach was applicable to the deduplication and exploitability determination of a large amount of UAF vulnerability samples, with high accuracy and low performance cost.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.5
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• pp.1932-1950
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• 2018

The paper proposes a code-clone detection method that gives the highest possible precision and recall, without giving much attention to efficiency and scalability. The goal is to automatically create a reliable reference corpus that can be used as a basis for evaluating the precision and recall of clone detection tools. The algorithm takes an abstract-syntax-tree representation of source code and thoroughly examines every possible pair of all duplicate tree patterns in the tree, while avoiding unnecessary and duplicated comparisons wherever possible. The largest possible duplicate patterns are then collected in the set of pattern clusters that are used to identify code clones. The method is implemented and evaluated for a standard set of open-source Java applications. The experimental result shows very high precision and recall. False-negative clones missed by our method are all non-contiguous clones. Finally, the concept of neighbor patterns, which can be used to improve recall by detecting non-contiguous clones and intertwined clones, is proposed.

• Annual Conference of KIPS
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• 2015.10a
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• pp.478-481
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• 2015

모바일 기기의 특성 중 하나인 제한된 전력은 중요한 문제로 다뤄지고 있다. 이러한 전력 문제를 해소하기 위해 다양한 모바일 저전력화 연구가 진행되고 있다. 이러한 연구들 중 전력 측정이 정확하지 않으면 저전력화 연구에 치명적인 오류를 가져올 수 있기 때문에 정확한 전력 측정은 다른 연구들의 근본이 된다고 할 수 있다. 이를 위해 포터블 전력 측정 장비(Portable Power Measurement and Analysis tools, PPAM)를 개발하였다. 그러나 포터블 전력 측정 장비는 높은 샘플링 주파수로 인한 방대한 양의 데이터를 텍스트로 출력한다. 이 데이터를 보다 효과적으로 분석하기 위해 본 논문에서는 데이터의 간소화와 시각화 등의 2가지 요구사항을 도출하였으며, 이를 충족하는 모바일 소프트웨어의 상태별 전력 소모 분석을 위한 뷰어 개발을 하였다. 이 뷰어를 사용함으로써 연구자는 소모 전력 데이터를 보다 직관적이며, 효율적으로 분석이 가능하다. 향후 이 뷰어는 포터블 전력 측정 장비와 함께 소프트웨어의 저전력화 연구에 도움이 될 것이다.

• Journal of the Korean Mathematical Society
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• v.58 no.6
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• pp.1461-1484
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• 2021

We deal with the following elliptic equations: $\{-div({\varphi}^{\prime}(\left|{\nabla}z\right|^2){\nabla}z)+V(x)\left|z\right|^{{\alpha}-2}z={\lambda}{\rho}(x)\left|z\right|^{r-2}z+h(x,z),\\z(x){\rightarrow}0,\;as\;\left|x\right|{\rightarrow}{\infty},$ in ℝ^N , where N ≥ 2, 1 < p < q < N, 1 < α ≤ p^*q'/p', α < q, 1 < r < min{p, α}, φ(t) behaves like t^q/2 for small t and t^p/2 for large t, and p' and q' the conjugate exponents of p and q, respectively. Here, V : ℝ^N → (0, ∞) is a potential function and h : ℝ^N × ℝ → ℝ is a Carathéodory function. The present paper is devoted to the existence of at least two distinct nontrivial solutions to quasilinear elliptic problems of Schrödinger type, which provides a concave-convex nature to the problem. The primary tools are the well-known mountain pass theorem and a variant of Ekeland's variational principle.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.5
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• pp.189-199
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• 2021

This study aimed to explore the factors affecting the innovation capacity of students at the National Economics University, Vietnam. Researchers used the innovation capacity model based on six factors, including personality traits, future orientation, creative skills, social interaction, content knowledge, and management skills. The empirical analysis used data from the survey of 303 students at National Economics University, Vietnam, with reliable tools (SPSS 26.0 software). The data were analyzed by testing the reliability of the scales, correlation analysis, and Pearson' Linear Correlation Coefficient, exploratory factor analysis, as well as regression model based on the survey data. The research results identified the following factors affecting innovation capacity of students: management skills, social interaction, and personality traits have the strongest impact on innovation capacity of students; content knowledge has the following strongest effects on innovation capacity of students; and finally the creative skills that affects on innovation capacity of students. There is also a positive relationship between all the factors and innovation capacity of students. The result can serve as useful reference sources for scholars who are interested in the innovation field. It also helps university's managers and policymakers build the appropriate environment to improve innovation capacity of students.

• The Journal of the Korea Contents Association
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• v.19 no.8
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• pp.214-223
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• 2019

This study was to review the research trends in domestic computing thinking and to suggest future research direction by analyzing 138 papers related to computing thinking published in domestic academic journals from 2015 to 2018. As a result, domestic research on computing thinking has been steadily increasing since 2015, and quantitative research, development research and experimental research were mainly used. Most research were conducted for elementary school students and university students. Research topics are oriented to the curriculum and program as well as the relationship among the variables related with computational thinking. It is necessary to explore empirical studies such as teaching methods, teaching tools, media utilization, and evaluation methods in order to promote learner's computing thinking. Also, it is needed to explore various variables related to enhance computing thinking and the relationship among the variables.

• International Journal of Knowledge Content Development & Technology
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• v.9 no.2
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• pp.45-64
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• 2019

This study examined the perception and use of web 2.0 applications for academic purposes by medical students of Ambrose Alli University, Ekpoma. The objective was to investigate the medical students' perceptions of web 2.0 applications, web 2.0 tools use, extent of use, perception and purpose for using web 2.0 applications. Descriptive survey method was used for this study. The total population of this study was 3670 and the sample size was 367 representing 10% of the study. The purposive sampling technique was adopted, and the instrument used for this study was questionnaire, a total of 367 copies were administered and 321 were found useful for the study. Percentage means and standard deviation on table and chart were used to analyze the data collected using Statistical Package for the Social Sciences (SPSS) software. Findings showed that the perception of web 2.0 applications of medical students AAU was positive and few of web 2.0 applications were used for academic purposes. It was recommended in the study that medical students should be provided with the facilities in a format more familiar to them and used by most of them and institutions need to equip the learning process with the needed facilities which will be of utmost benefit even for future purposes.